An El Niño advisory continues from the Climate Prediction Center (CPC).
A moderate El Niño continued throughout the equatorial Pacific during
March 2010. Deep tropical convection remained enhanced across central and eastern parts of
the tropical Pacific.
Southern California saw very little precipitation during March.

Current Observations

Warm equatorial waters can be seen
in an animation from the Climate Prediction Center of the weekly sea surface
temperature (SST) anomalies from January 20 to April 7, 2010:

The current forecast from the Experimental Climate Prediction Center at the
Scripps Institution of Oceanography is forecasting El Niño conditions
to return to neutral in the summer of 2010. Below is the forecast
sea surface temperature anomaly for the tropical Pacific covering the months
of June through August 2010.

Find more forecast images and information about this forecast on the
Experimental El Niño Forecast web page:

The graphics below show January sea surface temperature anomalies for previous strong
El Niños and the 2009/2010 El Niño.

The graphics below show January 700mb height anomalies for previous strong
El Niños and the 2009/2010 El Niño.

El Niño and California

California does not always see an increase
in precipitation during El Niño years.

Klaus Wolter (NOAA CIRES Climate Diagnostics Center, Boulder CO)
has developed a Multivariate ENSO Index (MEI) based on six observed variables
over the tropical Pacific: sea-level pressure, zonal wind, meridional wind,
sea surface temperature, surface air temperature and total cloudiness. The
time series of this index from 1950 to now is shown below. Red indicates times
of El Niño events. Click
here to see
the MEI web page that Klaus has put together (note this web page has many
El Niño related links).

In order to compare the current El Niño watch with previous events,
Klaus had made a figure showing the MEI for 7 of the strongest transition events since
1950, with the current event in black (see black dashed '09+' line).

While an El Niño doesn't gaurantee a wet winter in California,
the graphs below for San Diego (left) and an 8-station California index
(8 stations in Northern Sierra used by the California Department of
Water Resources, right),
show that more often than not, precipitation is above normal
during an El Niño:

From the Climate Prediction Center, we have an analysis of the El Niño
impact by state. These impacts are derived from looking at what happened
during moderate to strong El Niños of the last 100 years (1895-1997).
In the image below, California rankings are shown
for precipitation (top; wet [green] to dry [red]) and
temperature (bottom; cold [blue] to warm [red]) by climate division. These
rankings are for 3 three-month intervals over the winter-spring season:
November to January, January to March and March to May

November-January

January-March

March-May

Precipitation

November-January

January-March

March-May

Temperature

Other atmospheric patterns associated with El Niño are shown in
composites made using tools available from the Climate Diagnostics Center.
The ten El Niño years chosen for the composites below are:
1966, 1973, 1978, 1983, 1988, 1992, 1993, 1994, 1995, and 1998. These
composites are of data from the NCEP Reanalysis project (which covers the
period 1948-present).

700mb height anomalies (in meters)

Surface temperature anomalies (in degrees C)

Surface wind anomalies (in meters/second)

Correlation of November to March surface precipitation
with SST in the Niño3 region